Field of the Invention
The present invention relates to an image forming apparatus including a fixing unit that fixes a toner image formed on a recording material to the recording material.
Description of the Related Art
An image forming apparatus using an electrophotographic recording technique has a door openable and closable with respect to a main body of the image forming apparatus to enable a user to perform jam handling of a recording material, maintenance of the image forming apparatus, and replacement of a replaceable unit. When the door is open, the user may possibly touch the inside of a fixing unit via an inlet of the fixing unit and so on. To avoid this, some image forming apparatuses include in each of them a shutter that is provided to the inlet of the fixing unit and moves in conjunction with the opening and closing of the door(Japanese Patent Application Laid-Open No. 2014-170152).
According to Japanese Patent Application Laid-Open No. 2014-170152, a rotating area of the shutter is provided inside the fixing unit. This increases the fixing unit in size and increases the image forming apparatus in size as well.
The rotating area of the shutter can be configured to be provided outside the fixing unit. FIG. 12 illustrates an example of such a configuration. In FIG. 12, a fixing unit 150 includes a roller pair PR inside. The roller pair PR forms a nip portion N for heating and fixing an unfixed toner image T formed on a recording material S. An arrow CD indicates a conveyance direction of the recording material S. A shutter 161 is arranged on an inlet IN through which the recording material S is inserted into the fixing unit 150. The shutter 161 is arranged to be rotatable with regard to a shaft 161a. The shutter 161 moves to a position 161(close) in which to close the inlet IN, and a position 161(open) in which to open the inlet IN. The shutter 161 includes a abutment portion 161b with which the door (not illustrated) of the main body of the image forming apparatus comes into contact. If the door is closed, the abutment portion 161b undergoes force illustrated by an arrow DP from the door side. If the door is open or, in other words, the inlet IN is closed by the shutter 161, the abutment portion 161b is in a shutter position 161b(close). If the door is closed or, in other words, the inlet IN is open, the abutment portion 161b is in a shutter position 161b(open).
As described above, the door of the main body of the image forming apparatus is provided to enable the user to perform such processing as the jam handing of a recording material, the maintenance of the image forming apparatus, and the replacement of a replaceable unit. Such processing is performed with the door open. If the door is opened, the shutter 161 and the abutment portion 161b of the shutter 161 move to the position illustrated by the full lines (close position). If the abutment portion 161b here protrudes greatly from the fixing unit 150 as illustrated by a distance PX, the abutment portion 161a may interfere with the foregoing processing. In particular, when taking a replaceable unit out of the main body of the image forming apparatus, the replaceable unit may undesirably interfere with the abutment portion 161b. Increasing the image forming apparatus in size as much as the distance PX to avoid the interference is also undesirable.